1. Field of the Invention
The present invention relates to a method of consecutively carrying out heat sterilization of a sealed vessel such as a vial having an inside plug such as a rubber stopper and containing a liquid medicine and to an apparatus for carrying out the method.
2. Description of the Related Art
Conventionally, sterilization treatment of a vial containing a liquid medicine such as injection material has been conducted in the process of producing the filled vial. A method of steam sterilization using a high-pressure steam tank is well known as the above method. However, the above method of steam sterilization is a batch process which has not been associated with the filling process and it has not been able to immediately measure a temperature of each vial.
Consequently, each vial has not been independently detected as to whether the sterilization is completely carried out and a guarantee for the sterilization of each vial has depended on the condition of the whole batch.
Furthermore, a sealed vessel having an inside plug such as the rubber stopper does not allow measurement of the temperature of the inside plug, so that it has been difficult to guarantee that such a vial is sterilized.
However, in the method of sterilizing consecutively the sealed vessel such as the vial having the inside plug such as the rubber stopper, the inside plug should be sterilized to the same degree as the liquid medicine.
Also, heating from the outside of the vial by using a hot air as in a conventional consecutive sterilizer has not heated the vial sufficiently uniformly to completely sterilize the vial because of a usual aluminum-cap or a resin flip-cap covering the inside plug. The resin flip-cap may be destroyed by the hot air.